Figure 3.

Energy metabolism of cardiomyocytes. The figure describes the uptake of the most important energy substrates in the myocardium: carbohydrates (glucose), fatty acids, and ketone bodies (beta-hydroxybutyrate). Glucose is processed by glycolysis in the cytoplasm, followed by the entry of pyruvate into the mitochondria, where it is oxidatively decarboxylated with the formation of acetyl-CoA. The fatty acids are activated into acyl-CoA and transferred to the mitochondria linked to carnitine. In mitochondria, the process of beta-oxidation will generate more molecules of acetyl-CoA, and the ketone bodies represented by beta-hydroxybutyrate and acetoacetate are metabolized by ketolysis to acetyl-CoA. The acetyl-CoA formed is metabolized in the Krebs cycle with the formation of reduced coenzymes (NADH and FADH₂) that will be oxidized in the electron transport chain with energy formation, a part of which is stored in the form of ATP. (β(OH)B–β-hydroxybutyrate, FA–fatty acid, MCT–monocarboxylic acid transporter, CD 36–cluster of differentiation 36, FATP–fatty acid transport protein, GLUT–glucose transporter, MPC–mitochondrial pyruvate carrier, CPT 1 and 2–carnitine palmitoyl transferase 1 and 2, CT–carnitine translocase, PDH–pyruvate dehydrogenase, AcAc–acetoacetate, ETC–electron transfer chain). The text in red letters signifies enzymes and in green letters signifies transporters.